In the first instance, bolsters are designed with a design point of impact. The design point of impact is determined by assuming the position of a statistical male or female occupant. Ideally, the vehicle occupant is in a designated position and is using a seatbelt or other similar safety harness. However, because of the differentiation in size of the vehicle occupants and because not all vehicle occupants use seatbelts, and therefore the location of the occupant may not be as expected, the point of impact between the occupant and the bolster may occur at other than the most desirable design location. Vehicles also have many other envelope constraints as to the amount of space available for mounting a bolster. In many cases, the vehicle mounting envelope constraints confine a bolster to a certain lateral length. It would be desirable, however, that the bolster, when called upon to provide its safety function, have a greater lateral length.
As used in this description and claims, the term “lateral” is used to describe the transverse width of the bolster. If the bolster were mounted against an instrument panel, the lateral extent of the direction would be transverse of the vehicle. If the bolster were mounted to a door frame, the lateral extent of the bolster would extend longitudinally of the vehicle. If the bolster were mounted on an angular support pillar such as an A pillar, the lateral length of the bolster would extend longitudinally and angularly of the vehicle. In short, the term “lateral” is intended to encompass any mounting location of the bolster with regard to the vehicle.
In accordance with the information set out above, it would be desirable, if a bolster were able to increase its lateral extent upon activation.
Known in the art are the following patent and patent applications which disclose inflatable bolsters and the like: US 2007/0108747; U.S. Pat. No. 6,032,978; U.S. Pat. No. 6,203,057; U.S. Pat. No. 6,305,710; U.S. Pat. No. 6,517,103; U.S. Pat. No. 6,578,867; U.S. Pat. No. 6,619,689; U.S. Pat. No. 6,758,493; U.S. Pat. No. 6,848,715; U.S. Pat. No. 6,976,706; U.S. Pat. No. 7,350,852; and WO 2006/132990.